Can you please tell me the difference between Opera, Opera Club and Opera Master?

Thanks

Opera = black resin, etched, cartridge-converter
Opera Master = oversized, black etched or clear swirled demo or amber or blue, double-reservoir power filler
Opera Club = colors, cartridge-converter

Opera and Opera Club are the same pen, 14 Kt nib, converter filled; one black with linedrawing design:


and one colored:


The Opera Master is much bigger, "double reservoir" piston filling, 18 Kt gold nib; one black,
and three Demo, in different colours:

Thank you. I need to get one!